Defense Department officials say shots were fired at the Pentagon building just outside Washington on Tuesday.
Pentagon police say they are investigating reports that several shots were fired near the building in the pre-dawn hours. An initial investigation found evidence that at least two bullets had struck the Pentagon.
Law enforcement officials closed a major highway and several other roads adjacent to the building to search for evidence. It is unclear how many shots were fired or what type of weapon was used.
No injuries have been reported.
Some information for this report was provided by AP.